Tribute 4WD L4-2.3L Hybrid (2008)
Discharge Air Temperature Sensor / Switch: Description and Operation
AUXILIARY EVAPORATOR DISCHARGE AIR TEMPERATURE SENSOR
The auxiliary evaporator discharge air temperature sensor contains a thermistor which communicates the auxiliary evaporator air discharge temperature
to the TBCM. The TBCM then sends a signal to the PCM to indicate if the auxiliary discharge air temperature signal is indicating a freeze or no-freeze
condition.
When the A/C is operating for HVTB cooling, but has not been requested for the passenger compartment, the PCM prevents icing of the auxiliary
evaporator core. It does this by switching off the A/C compressor when the TBCM indicates the auxiliary evaporator discharge air temperature sensor
reading has fallen below acceptable levels, and by switching on the A/C compressor when the auxiliary evaporator temperature rises above acceptable
levels.
When the A/C is operating for both the passenger compartment and HVTB cooling, the A/C compressor will continue to run (A/C request will remain
ON), and the battery zone valve will be closed by the PCM if the auxiliary evaporator discharge air temperature sensor is reading a temperature below
acceptable levels. This allows continued refrigerant flow to the front (main) evaporator core, while allowing the auxiliary evaporator core to warm to
acceptable levels.
The evaporator discharge air temperature sensor is located on the auxiliary climate control housing.
